Horizontal return fire tube boiler having a central furnace with double outlet



April 22, 1952 A. s. WELDY 2,593,946 HORIZONTAL RETURN FIRE TUBE BOILER HAVING A CENTRAL FURNACE WITH DOUBLE OUTLET Filed Dec. 31, 1948 3; BY wag 5% forming part of the specification. understood, however, that variations in the show- Patented Apr. 22, 1952 "HORIZONTAL RETURN FIRE "TUBE "BOILER HAVING AGENTRAL FURNACE WITH DOU- BLE OUTLET Arthur s. Weldy, MountEden, Calif. Application December 31, 11948, Serial'No. 68;518

3 Claims. 1 The invention relates to boilers and more particularly constructions utilizing a plurality of boiler units in conjunction with a common centrally arranged fire box.

An objectof the. present invention is to provide a boiler of the character described wherein a plurality of boiler units or sections are unitarily assembled with respect -to a common fire box and are constructed and arranged so as to provide anyimproved utilization andsaving of heat with a consequent improvementin efiiciency of opera- .tion.

Another object of the invention is to'provide a boiler of the character above which willyafford an improved flexibility in operation in that the individual sections may be employed in various arrangements and combinations for the production of hot water or steam, or both.

A further object of the present inventionis to provide a boiler of the character described which may be easily and'readily constructed by assemdamage in the event of flashback or explosive burning iirthe flue tubes.

"The invention possesses other objects and fea- "tures of advantage, some of which; with the foregoing,'-will be set forth'in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and It is to be ing made by'the said drawing and description -may be adopted within thescope of the invention as set forth in the claims.

'Referringto said drawing: I Figure 1 is a side elevation of a'boiler constructe'din accordance with the presentinvention.

Figure 2 1s ca transverse sectional viewtaken substantially on .theplane of line 2-- 2 of Figure 1.

Figure 3 is a, longitudinal sectional view of the 'boiler taken substantially on the plane of line .trated. in "the accompanying drawing, comprises ea pairofrcontainers Gand Horifiuidtobe heated,

'mounted in generally horizontal alignment upon a base support 8. The latter is hereshowm constructed of refractory material such as firebrick,

and provides an-open topped fire box 9 .defined between upstandingside walls 5H and l2, -end walls !3 and I4, and-a raised bottom wall IS. The

mounting of the containers 6 and 1 onuthefbase support is such that the adjacent ends Hand 18 of the containers overlie the sides. and ends of: the base support and extend into the firebox enclosure defined thereby, see Figure ,3. As animportant feature of the present invention,lthe:ad jacent end walls l9 andZl of the containers. are arranged in spaced substantiallyparallel vertical planes'so as to define-a passagewaylz therebetween registering with and providing a vertical extension of the fire'boxs. Anysuitable typelof conventional. burner 23 maybe: mounted within the fire box 9 and access :to .theqburner andlthe fire box is afforded through an openingiinflthe side wall l2, normally coveredby a door 101F010- sure plate 24.

In. accordance with the present invention; and

l as. a principal feature thereofyathermalconnection is provided between the end walls l9 "and 2| of thecontainersin theforrn of ,a .balile extending into thepassageway 22 ,in ,suclra-manner asctobe heated by direct ;conduc tion:;a-nd radiation fromthe; firebox and being operative to transfer its;heat by qconduction to the end walls [9 and 2| of the containers. Preferably, suchmeans extends completely acrossthe passageway'ZZ sojasto provide a closedtop "for the fire box, *andis additionally ;of hollow-Construction, so as, to contain Within-the lbafiievfluid vf-rom the containers :to ;be heated. This arrangement is accomplished in the present construction :-by

the provision on therendrwalls. l9 andZ l :ofout- :wardly proj acting hollow ribs l 26 -and ;27 which extend transversely across lithe :end; walls 3 l 9 and 2 l in substantially ahorizontalplaneand-project outwardly from the :end walls :into the massageway .22 and into abutting :"re1ation,,;so 12,15 to .define'atop enclosure; for the passageway. The ribs are preferably pressed zoutnof:the enficwal I 9 and-l2 l approximately :centrally 0f: the lheig-ht thereof 'andyarranged with the hollow interiors ,23 and 29:0f the ribs'xin directcommunication with :the interiors of :theirtrespective containers 6 and J1. Alsoysince the ribs-projectoutrinto the passageway 22 approximately centrally of and directly overitlie fire box v9; these ri'bs-willlgbe directly heated by :the :products "01 :comhustion originating in theme box19..;such heating, of

:course, being effected :by both -;-conduction of 3 heat by the products and radiation from the fire box. In this manner, the fluid contained within the hollow interiors 28 and 29 of the ribs will be rapidly heated. Additionally and as an important feature of the present invention, means is provided for conducting the heat from the ribs 26 and 21 directly into the interiors of the containers 6 and 1. This means is here in the form of heat conducting plates 3| and 32, which are secured, as by welding or the like, to the interior apex of the ribs 26 and 21 and extend horizontally therefrom into the interior of the containers.

Preferably and as will be seen from Figure 2, these plates extend across substantially the full width-wise dimension of the containers.

The heated products of combustion generated in the fire box 9 are conducted through containers 6 and 1 by a plurality of the flue tubes 33 and 34 which extend horizontally and longitudinally through the containers from the end walls It and 2|, below the ribs 26 and 21, to flue chambers 3B and 3! in the outer ends of the containers. These chambers are provided with end enclosure members 38 and 39 covering in spaced relation the outer end walls 4| and 12 of the containers. As will be seen from Figure 3 the opposite ends of the flue tubes 33 and 34 are secured to and extend through the container end walls 59 and 4|, and 2| and 42, so that the heated products of combustion will pass from the fire box longitudinally through the tubes 33 and 34 in intimate heat exchange relation with the content of the containers and emerge into the end chambers 36 and 31. From these end chambers, the products are directed back through the containers 6 and by a plurality of flue tubes 43 and M extending longitudinally through the containers above the plane of the ribs 26 and H, the latter tubes being also secured to and extending through the opposite end walls l9 and ll, and 2| and d2 of the containers. In this manner, the products of combustion are delivered at the discharge ends of tubes 33 and 44, into a flue discharge chamber 46 defined in the space between the adjacent end walls H3 and 2| above the plane of the ribs 1 26 and 21. Desirably, a smoke hood 41 is surmounted on the adjacent ends I! and is of the containers so as to provide an enclosure for the flue chamber 46, and is additionally formed with a flue outlet opening d8 defined within a collar 49.

As an important feature of the present construction, means is provided for relieving sudden or instantaneous surges of pressure within the boiler such as may be occasioned by a flashback in burning or combustion explosions occurring within the flue tubes. 'here provided in the end flue chambers 3t and 31 in the form of relief valves and 52 carried Such means is by the end enclosure member 33 and. 35. Preferably. these valves are of a simple gravity closing type consisting of doors hinged at their upper extremities to horizontallyexteriding pivot pins 53 and 54 and being normally supported in a generally downward and outwardly inclined position on annular seats 56 and 51 surrounding exit openings 58 and 53 in the members 38 and "39. In this manner, a sudden surge of pressure within the end chambers 33 and 3'! will force the doors 5| and 52 to swing outwardly away from their seats and thereby vent the pressure to the atmosphere, the doors thereafter returning by gravity to their seated position.

Water or other fluid is fed into and removed "from the containers 3 and 1 by independent 4 piping connections so that individual or separate operation of the units may be maintained. As here shown, inlet pipes iii and 62 extend from the top sides of the containers 6 and 1 to the lower levels of the interiors of the containers, where the inlet water or other fluid is discharged in intimate contact with the lower flue tubes 33 and 36. Preferably, the pipes ti and 32 are flattened in a longitudinal vertical plane, as illustrated in Figures 2 and 3, so as to fit within the plurality of flue tubes within the containers while affording an enlarged volume input. Discharge pipes 63 and extend from the upper sides oi. the containers 6 and l for removal of the heated fluid from the upper regions of the containers. If desired, clean-out openings 65 and 31 may be provided on the bottoms of the containers 6 and I.

Preferably, the containers 6 and I are constructed of substantially cylindrical shells and are mounted on the base support in approximately coaxial relation. To accommodate and support the cylindrical form of the shells, the opposite end walls I3 and it are relieved to provide concave seats 38 fitting around approximately the lower half of the circumference of the shells, see Figure 2, these seats also functioning to seal the shells in the end walls. On the other hand, the side walls H and i2 extend up to approximately the central plane of the shells to substantially contact the periphery of the shells thereat. As an important feature of the present construction, the shells are provided with outstanding flanges 69 and H which lie in substantially the central horizontal plane of the shells and rest directly upon and are supported by the upper ends of side walls l! and I2, to thereby seal the containers to such side walls. Additionally, the flanges t9 and H are preferably constructed of steel or other heat-conducting material, so as to transfer heat from the side walls of the fire box to the containers. The flanges 69 and ii also afford a support for the opposite sides i2 and E3 of the smoke hood 41, the sides l2 and '53 having out-turned base flanges i4 and 16 mounted directly upon the upper sides of the flanges 69 and H. A plurality of bolts ll may be imbedded in the upper extremities of the side walls I l and I2 for securing the flanges 63, l I, Hi and iii in place.

The mounting construction for the individual boiler units above described permits a simple and ready assembling of the boiler or a subsequent there is no direct water, connection between the two containers, one may be used for the produc- 1131011 of hot water while the other is used to produce steam, or both may be used for hot water or steam, as may be desired. The units may be connected in series where a temperature boosting effect is required, or the units may be connected in parallel where increased output is required. Where the units are connected in series, hot water may be taken off from the first unit and steam from the second unit. Or, if desired, any other external booster heater may be connected toeither one or both of the units. While such flexibility .of theuse and application ofthe boiler is afiorded in the present construction, it will be likewise understood from the foregoing that the construction and arrangement of the units is such as to provide a maximum heat transfer and utilization of heat whereby efficiency of operation is assured.

I claim:

1. A boiler comprising, a pair of containers for fluid to be heated mounted in substantially horizontal alignment with adjacent ends in spaced substantially parallel relation defining a vertical passageway therebetween, means providing a fire box underlying said ends and in registration with said passageway, said ends being formed with extensions defining a substantially horizontal bafile in said passageway positioned for heating by direct radiation from said fire box, and plates of heat-conducting material connected to said extensions and extending interiorly in said containers for heating the contents thereof.

2. A boiler comprising, a pair of containers for fluid to be heated, mounted in substantially horizontal alignment with adjacent ends in spaced substantially parallel relation defining a vertical passageway therebetween, said ends providing a seal between said containers so as to prevent flow of fluid therebetween, means providing a fire box underlying said ends and in vertical registration with said passageway, U-shaped ribs provided on and extending transversely across said ends and projecting into said passageway and into abutting relation to define a closure for said passageway, said ribs being positioned for heating by direct radiation from said fire box and having the hollow interiors thereof in communication with the interiors of said containers for filling of said ribs with fluid to be heated. boiler flue tubes extending from said passageway through and exteriorly of said containers, and plates of heat-conducting material carried by said ribs and extending interiorly of said containers for heating the contents therein.

3. A boiler comprising, a support providing a fire box having opposed sides and an open top, a pair of independent containers for fluid to be heated and each formed with side flanges of heat-conducting material projecting from the opposite sides thereof, the said containers each being sealed relative to the other so as to prevent the flow of fluid therebetween, said flanges being mounted upon the upper extremities of said fire box sides to seal said containers thereon, the adjacent ends of said containers being arranged in spaced substantially parallel relation defining a vertical passageway there-between registering with said fire box, said ends being formed with medial extensions abutting each other along a substantially horizontal line within and dividing said passageway into upper and lower portions, and defining a closed top for said fire box, a hood mounted on said flanges and surrounding and enclosing said container ends above said extensions to define a flue discharge chamber in communication with said upper passageway portion, and separate flue tubes extendin through each of said containers and connecting said passageway with said chamber, and means intermediate said passageway and chamber providing a pressure relief valve for the heated gases in said flue tubes.

ARTHUR S. WELDY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 123,767 Brackney Feb. 20, 1872 152,100 Fuller June 16, 1874 387,317 Ritchie Aug 7, 1888 490,741 Engel Jan. 31, 1893 617,050 Richards et a1 Jan. 3, 1899 645,507 Humphrey Mar. 13, 1900 730,409 Smith June 9, 1903 871,201 Bonus Nov. 19, 1907 1,105,526 McClellon July 28, 1914 1,696,206 Lange Dec. 25, 1928 2,034,782 Thomes Mar. 24, 1936 2,080,404 Hunter et al May 18, 1937 2,241,209 Lea May 6, 1941 2,311,484 Stack Feb. 16, 1943 

